Resin manufacture



Patented Jan. 12, 1943 UNITED STATES PATENT OFFICE RESIN MANUFACTURE NoDrawing. Original application March 30,

1939, Serial No.

7 Claims.

This invention relates to a method of producing a resin and moreparticularly to a method of producing from resinous wood a resincharacterized by substantial insolubility in light petroleumhydrocarbons.

It has been the practice heretofore to treat resinous wood such as, forexample, pine chips in order to extract therefrom rosin and variousvolatile terpenes such as turpentine and pine oil. Gasoline, forexample, has been widely used in the extraction of rosin from pine woodand the total resinous matter so extracted is commonly known in the artas FF rosin. However, a solvent which comprises a coal tar hydrocarbonsuch as, for example, benzene, toluene, xylene, etc, has the property ofextracting from pine wood, e. g., wood of the long leaf pine desirablyin suitable form such as chips, resinous material not extracted fromsuch wood by the use of gasoline or other light petroleum hydrocarbons.Solvents of the coal tar hydrocarbon type will, therefore, extract frompine wood a larger quantity of resinous material.

It has been the practice heretofore to take the crude extract, obtainedfrom extracting pine wood with a solvent of the coal tar hydrocarbontype, such as benzene and toluene, remove the solvent and volatileterpene' oils by suitable means, thus recovering a solid resinousresidue consisting principally of FF rosin and a resinous substanceother than rosin. Heretofore this resinous residue has been separated bymeans of a pair of selective solvents, such as, for example, gasolineand furfural, although many other pairs of solvents are also known whichwill effect this separation. When the gasoline-furfural combination isused, rosin dissolves in the gasoline and the resinous substance otherthan rosin, dissolves in the furfural, since this substance issubstantially insoluble in petroleum type hydrocarbons. Evaporation ofthe furfural then leaves this resinous substance as a solid mass.

It is an object of this invention to provide a method whereby aseparation of the resinous components of pine wood can be made in asimpler manner than heretofore done, directly obtainingv thereby theresinous component which is substantially insoluble in light petroleumhydrocarbons.

It is also an object to provide a method whereby the resinous componentsubstantially insoluble in gasoline may be directly obtained in apulverulent, free-flowing form. The resin in this form, is desirable formany purposes. By prior art methods it has been necessary to chill the264,971. Divided and this application February 25, 1942,

Serial No. 432,249

solid resin, obtained as before shown, and then pulverize it to obtainit in a pulverulent form. This is an additional step and adds to thecost of the resin. Other objects and advantages of the invention will beapparent during the course of the following description.

The objects of my invention are accomplished by treating pine Wood witha solvent which is capable of dissolving the normally solid resinousmaterials and terpene oils present in said wood, separating the extractso obtained from the wood", diluting this extract with a sufiicientquantity of a substantially saturated paraffin hydrocarbon toprecipitate that portion of the original extract which is substantiallyinsoluble in so]- vents of this type, separating the residue so obtainedfrom the remainder of the solution and drying this residue. The solutioncontaining the extraction and precipitating solvents as well as theterpene oils and rosin may be suitably treated for the recovery of allthe components. The extraction and precipitating solvents may be reusedin the process.

The temperatures used in diluting, for example, a coal tar hydrocarbonextract of pine wood, with a substantially saturated parafin hydrocarbonmay vary over quite a range and the form of the precipitate will dependchiefly on the temperature used. If. the form of the precipitate is ofno particular moment, relatively high temperatures may be used but forease of separation of the precipitate and in order to obtain a residuewhich, when dried, is in a pulverulent, free-flowing form, I have foundthat a temperature not over about 20 C. is desirable.

While I will now describe my invention particularly by reference to thepreparation of a pulverulent, free-flowing product, it will beunderstood that the process as described is broadly applicable to thetreatment of a solvent extract of pine wood containing the normallysolid resinous materials and terpene oils to obtain directly from thissolution a resin substantially insoluble in light petroleumhydrocarbons.

In proceeding in accordance with my invention, pine wood, preferablythat from the Southcm long leaf pine in suitable form such as, forexample, chips, may be extracted with a solvent for the FF rosin,turpentine and pine oil contained in the chips and which is likewise asolvent for the other complex substances contained in the wood chips.Such a solvent may be, for example, a coal tar hydrocarbon such as,benzene, toluene, xylene, etc., and the extraction may be accomplishedby flooding pine chips with the solvent with or without the use of heat.After the extraction of the chips has beensufficient, the coal tarhydrocarbon solution of the matter extracted may be withdrawn from thewood chips.

To recover a pulverulent, free-flowing resin substantially insoluble inlight petroleum hydrocarbons from the solution extract obtained from thepine chips as shown above, I may proceed in the following manner:

I may take the crude liquor obtained from the extraction of pine chipsand dilute this crude liquor with a substantially saturated, paraffinhydrocarbon at a temperature not higher than about C. therebyprecipitating an insoluble fraction in the form of a powderyprecipitate. This precipitate may be readily and easily filtered from vthe solution and, after drying, will be in the form of a pulverulent,free-flowing resinous susbtance substantially insoluble in lightpetroleum hydrocarbons. Drying of the precipitated material may becarried out in any number of devices such as for example, a rotary kilndrier, a tunnel drier or a vacuum drier.

The filtrate may be subjected to distillation, yielding a distillatecontaining pine oil, turpentine, and the particular solvents used in theprocess and the residue remaining will be rosin having propertiescomparable to those of present crude'pale rosin. If the solvents used inmy process are so chosen that there is a relatively wide separation inboiling points, not only between themselves but between them and theturpentine and pine oil, fractional distillation will yield all of thecomponents in quite pure form. The solvents used in this process and sorecovered, may then be used for the treatment of successive crudeliquors.

The amount of substantially saturated paraffin hydrocarbon I may use inaccordance with my invention will depend upon the particular paraiiinhydrocarbon used as well as the solvent initially used in extracting thepine wood. The amount used will vary in each particular case and will beso chosen as to produce a finely divided precipitate, which, afterdrying, will yield a pulverulent, free-flowing product.

Among the substantially saturated paraflin hydrocarbons which I may usein accordance with my invention are butane, propane, pentane, hexane orvarious mixtures of these as well as low boiling petroleum distillatesand petroleum ether substantially free from aromatic compounds. It willbe understood, of course, that when using hydrocarbons which arenormally gaseous, it will be necessary to use temperatures sufficientlylow or pressures sufficiently high to have these hydrocarbons in theliquid state.

Among the solvents which I may use for extracting the pine wood armethyl and ethyl alcohol, acetone, ethyl acetate and coal tarhydrocarbons such as, for example, benzene, toluene and xylene. Of thesesolvents I prefer using a coal tar hydrocarbon, especially benzene ortoluene.

Having now shown the general mode of procedure, I will proceed to a moredetailed description thereof by reference to the following examples.

Example 1 Four hundred grams (400) of pentane cooled to 16 C. and 400grams of benzene extract of pine wood cooled to 0 C. were mixed,whereupon a. flocculent, granular precipitate was formed. Theprecipitate wa filtered off and dried giving a yield of 19.4% of apulverulent, free-flowing resin characterized by substantialinsolubility in light petroleum hydrocarbons.

Example 2 The same materials and the same quantity thereof as in Example1 Were used but instead of cooling, as before, both portions were cooledto +4 to +5 C. before mixing; a fiocculent, granular precipitate wasagain obtained which was Five hundred grams (500) of pentane were addedto 500 grams of a benzene extract of pine wood at a temperature of 30C., whereupon a fiocculent, yellow precipitate was formed. Theprecipitate was filtered off and dried, giving a yield of 12%. The resinso obtained is characterized by being substantially insoluble in lightpetroleum hydrocarbons but is not quite freefiowing as in the previousexamples wher a lower temperature was used. When the filtrate isevaporated, an 88% yield of resin is obtained.

It will be understood that the details and examples given hereinbeforeare illustrative only and in no way limiting on my invention as broadlydescribed hereinbefore and in the appended claims.

This application forms a division of my application, Serial No. 264,971,filed March 30, 1939.

What I claim and desire to protect by Letters- Patent is:

1. A method of directly producing a resin which is substantiallyinsoluble in light petroleum hydrocarbons which includes extracting pinewood with an organic solvent which dissolves the normally solid resinousmaterials and terpene oils present in said wood, separating the extractso obtained from the wood, diluting said solvent extract with asufficient quantity of butane to precipitate that portion of theresinous materials which is substantially insoluble in butane,separating said insoluble portion from the solution and drying theresidue.

2. A method of directly producing a resin which is substantiallyinsoluble in light petroleum hydrocarbons which includes extracting pinewood with a coal tar hydrocarbon which dissolves the normally solidresinous materials and terpene oils present in said wood, separating theextract so obtained from the wood, diluting said coal tar hydrocarbonextract with butane in an amount sufiicient to precipitate that portionof the resinous materials which is substantially insoluble in butane,separating said insoluble portion from the solution and drying theresidue.

3. A method of directly producing a resin which is substantiallyinsoluble in light petroleum hydrocarbons which includes extracting pinewood with benzene, said extract containing the normally solid resinousmaterials and terpene oils present in said wood, diluting said benzeneextract with butane in an amount sufficient to precipitate that portionof the resinous materials from the benzene extract which issubstantially insoluble in butane, separating said insoluble portionfrom the solution and drying the residue.

4. A method of directly producing a resin which is substantiallyinsoluble in light petro leum hydrocarbons which includes extractingpine wood with toluene, said extract containing the normally solidresinous materials and terpene oils present in said wood, diluting saidtoluene extract with butane in an amount sufficient to precipitate thatportion of the resinous materials from the toluene extract which issubstantially insoluble in butane, separating said insoluble portionfrom the solution and drying the residue.

5. A method of directly producing a pulverulent, free-flowing resinwhich is substantially insoluble in light petroleum hydrocarbons whichincludes extracting pine wood with a coal tar hydrocarbon whichdissolves the normally solid resinous materials and terpene oils presentin said wood, separating the coal tar hydrocarbon extract from the wood,adding to said extract at a temperature not above about 20 C. asuflicient quantity of butane to precipitate from said extract aninsoluble residue in finely divided form, separating this insolubleresidue from the solution and drying said residue to obtain apulverulent, free-flowing resin having the aforesaid characteristic.

6. A method of directly producing a pulverulent, free-flowing resinwhich is substantially insoluble in light petroleum hydrocarbons whichincludes extracting pine wood with benzene which dissolves the normallysolid resinous materials and terpene oils present in said wood,separating the benzene extract from the wood and adding to said extractat a temperature not above about 20 C. a sufficient quantity of butaneto precipitate from said extract an insoluble residue in finely dividedform, separating this insoluble residue from the solution and dryingsaid residue to obtain a pulverulent, freeflowing resin having theaforesaid characteristic.

'7. A method of directly producing a pulverulent, free-flowing resinwhich is substantially insoluble in light petroleum hydrocarbons whichincludes extracting pine wood with toluene which dissolves the normallysolid resinous material and terpene oils present in said wood,separating the toluene extract from the wood and adding to said extractat a temperature not above about 20 C. a sufficient quantity of butaneto precipitate from said extract an insoluble residue in finely dividedform, separating this insoluble residue from the solution and dryingsaid residue to obtain a pulverulent, free-flowing resin having theaforesaid characteristic.

ROBERT W. MARTIN.

